On One Numerical Scheme for Solving Radiative Transfer Equations in the Diffusion Approximation

The article presents a numerical technique for solving equations that describe the process of radiative transfer in protostellar disks. The proposed method expands the previously developed original computational gas-dust model of the star formation process using multi-level nested grids, which takes into account thermal radiation. In this article, we will consider three numerical schemes for three model equations describing the heat equation, the equilibrium and nonequilibrium radiative transfer models. All three model equations are parabolic, which, with the requirement to use a hydrodynamic time step, leads to the use of implicit schemes. In this work, to solve systems of linear algebraic equations, we used a fairly robust BiCGStab scheme with Jacobi preconditioning. Model problems demonstrate the robustness of the developed methodology.